"The aim wasn’t to have this terrifying encounter but to see these animals up close doing what they naturally do," Buchanan told the BBC's Radio Times magazine.

"This female could smell me inside and decided to investigate. She was pushing it very hard and at one stage came very close to pushing it over. That would have been a problem because on the underside there was just a bit of plywood. It was very disconcerting!"

For almost 45-minutes Buchanan endured the polar bear's sustained assault as it desperately looked for a weak spot in his pod. The bear, with its powerful paws and giant teeth, was trying to get hold of the 40-year-old so she could feed herself and her two young cubs.

Dubbed "the Indiana Jones of Natural History", Scotsman Buchanan grew up watching David Attenborough's BBC natural history shows before getting his big break on a documentary in Sierra Leone.

After working on shows such as Big Cat Diary, he made The Bear Family & Me, a three-part documentary series following his year with wild black bears in the forests of Minnesota, USA.

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